Some tourists in the Chicago Museum of Natural History are
marveling at
the dinosaur bones. One of them asks the guard, "Can you tell me how
old
the dinosaur bones are?"

The guard replies, "They are 73 million, four years, and six months
old."

"That's an awfully exact number," says the tourist. "How do you know
their age so precisely?"

The guard answers, "Well, the dinosaur bones were seventy three million
years old when I started working here, and that was four and a half
years ago."
[an error occurred while processing this directive]